U.S. patent number 4,154,354 [Application Number 05/890,938] was granted by the patent office on 1979-05-15 for safety container closures.
This patent grant is currently assigned to Lyn Trevor Evans, Trevor Gwilym Evans, Geoffrey Alan Ryder. Invention is credited to Geoffrey A. Ryder.
United States Patent |
4,154,354 |
Ryder |
May 15, 1979 |
Safety container closures
Abstract
A child-resistant closure cap for fitting to an externally
screw-threaded neck of a bottle is formed as a single integral
injection moulding, preferably of polypropylene, forming an
internally screw-threaded skirt, a bowed top wall which closes the
top of the skirt, a force-applying member on the upper face of the
top wall and lugs around the periphery of the underside of the top
wall. The top wall is movable for snap action by the application to
it of a force through the force-applying member between an upwardly
bowed position and a downwardly bowed position. When the top wall
is in the downwardly bowed position, the lugs engage with inward
projections on the inside of the neck of the bottle and this
prevents the closure cap from being unscrewed from the bottle. When
the top wall is snapped into its upwardly bowed position, the lugs
are moved clear of the inward projections and the cap can then be
unscrewed.
Inventors: |
Ryder; Geoffrey A. (Welwyn
Garden City, Hertfordshire, GB2) |
Assignee: |
Evans; Trevor Gwilym
(Hertfordshire, GB2)
Ryder; Geoffrey Alan (Hertfordshire, GB2)
Evans; Lyn Trevor (Hertfordshire, GB2)
|
Family
ID: |
10131165 |
Appl.
No.: |
05/890,938 |
Filed: |
March 28, 1978 |
Foreign Application Priority Data
|
|
|
|
|
May 10, 1977 [GB] |
|
|
19544/77 |
|
Current U.S.
Class: |
215/216;
215/330 |
Current CPC
Class: |
B65D
50/046 (20130101) |
Current International
Class: |
B65D
50/04 (20060101); B65D 50/00 (20060101); B65D
055/02 (); B65D 085/56 () |
Field of
Search: |
;215/214,216,217,330,301 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Hall; George T.
Attorney, Agent or Firm: Larson, Taylor and Hinds
Claims
I claim:
1. In a safety closure cap for fitting to an externally
screw-threaded neck or side wall of a container to close the
container, said cap comprising a single integral injection moulding
of thermoplastic plastics material, said moulding comprising an
annular skirt, an internal screw thread in said skirt for screwing
on to said neck or side wall, a top wall which closes the top of
said skirt, a locking part and engaging means on said locking part,
said locking part being movable upwardly and downwardly between a
lower position in which said engaging means engages with
projections on said container to prevent unscrewing of said cap
from said container and an upper position in which said engaging
means are clear of said projections to permit unscrewing of said
cap, the improvement wherein said top wall is bowed and forms said
locking part, said engaging means extend downwards from a
peripheral portion of said top wall for engagement with said
projections which extend inwardly internally of said neck or side
wall, and means is provided on the upper face of said top wall
enabling an upward or downward force to be applied selectively to
said top wall, said top wall being movable with a snap action by
the application of said downward force into a downwardly bowed
position in which said engaging means engage with said projections
to prevent unscrewing of said cap from said container and being
movable by the application of said upward force into an upwardly
bowed position in which said engaging means are clear of said
projections to allow unscrewing of said cap from said
container.
2. A closure cap as claimed in claim 1, wherein said top wall
includes two concentric annular hinges, said hinges being
constituted by thin sections of said resilient plastics
material.
3. A closure cap as claimed in claim 2, wherein said top wall
comprises a horizontal annular peripheral portion, a further
annular portion within said peripheral portion, and a centre
portion within said further annular portion, said peripheral
portion being connected to said further annular portion by one of
said two concentric annular hinges and said further annular portion
being connected to said centre portion by a second of said two
concentric annular hinges.
4. A closure cap as claimed in claim 3, wherein said means provided
on said upper face of said top wall comprises outwardly projecting
flange means and web means connecting said flange means to said
centre portion, part of said flange means extending closely
adjacent said annular peripheral portion and a remaining part of
said flange means being in contact with said annular peripheral
portion when said top wall is in said downwardly bowed
position.
5. A closure cap as claimed in claim 4, in which said web means is
resilient and flexible, whereby downward pressure on said part of
said flange means tilts said flange to move said remaining part
away from said annular peripheral portion to enable a finger to be
inserted under said remaining part to lift said top wall into said
upwardly bowed position.
6. A closure cap as claimed in claim 1, wherein said engaging means
on said top wall comprises a plurality of circumferentially spaced
lugs, said lugs being movable downwards and radially outwards as
said top wall is moved from said upwardly bowed position to said
downwardly bowed position.
7. A closure cap as claimed in claim 1, further comprising a
sealing ring moulded integrally with said top wall, said sealing
ring being adapted to engage sealingly with an end surface of said
neck of said side wall of said container when said cap is screwed
on to said container.
8. A closure cap as claimed in claim 1, in which said plastics
material is polypropylene.
9. A closure cap as claimed in claim 1, in combination with a
container, said container including a neck or side wall, an
external screw thread on said neck or side wall, said closure cap
being screwed on to said external screw thread, and a plurality of
inward projections projecting radially inwardly from said neck or
side wall, said engaging means being engageable with said
projections when said top wall is in said downwardly bowed
position.
10. The combination as claimed in claim 9, wherein said inward
projections are in the form of ratchet teeth to enable said cap to
be screwed on to said container while said top wall is in said
downwardly bowed position.
Description
This invention relates to safety closure caps, which are
child-resistant, for fitting to an externally screw-threaded neck
or side wall of a container to close the container.
There are various forms of closure cap which are constructed in
such a way that opening of the cap is not a straightforward
operation and therefore makes it difficult for a young child to
carry out. One such cap, which is disclosed in U.S. Pat. No.
3,698,584, comprises a single integral injection moulding of
thermoplastic plastics material forming an internally
screw-threaded skirt, a top wall which closes the top of the skirt
and a locking part which is movable upwardly and downwardly with a
snap action between a lower position in which engaging means
carried by the locking part engages with projections on the
container and prevents unscrewing of the cap, and an upper position
in which the engaging means are clear of the projections to permit
the cap to be unscrewed.
In the cap disclosed in the above-mentioned United States
Specification, the locking part is in the form of a ring which
surrounds the lower edge of the skirt and is connected to the
bottom of the skirt by a number of angularly spaced integrally
moulded strips of the plastics material. These strips are hinged
both to the bottom of the skirt and to the ring and this enables
the ring to be moved upwards and downwards relatively to the skirt.
The ring has a number of radially inwardly projecting teeth which,
when the ring is in its lower position engage with teeth provided
around the bottom of the neck of a bottle onto which the cap is
screwed and this interengagement prevents the cap from being
unscrewed.
This form of cap is simple and relatively inexpensive to
manufacture since it consists of a single integral injection
moulding of thermoplastic plastics material, but its degree of
resistance to opening by young children is not entirely
adequate.
Thus, although it may not be apparent to a young child that it is
necessary to lift the locking ring before it is possible to unscrew
the cap, there is a tendency, if a young child plays with the cap
when it is screwed on to a bottle, for the child inadvertently to
lift the locking ring so that it snaps into its upper position and
the child can then quite easily unscrew the cap and gain access to
its contents. Particularly if a young child puts the cap into its
mouth, then the locking ring can easily be pulled by the child's
teeth into its upper unlocked position.
The aim of the present invention is to provide a safety closure cap
which comprises a single integral injection moulding forming an
internally screw-threaded skirt, a top wall and a locking part as
described above, wherein the locking part is so disposed that the
risk of it being moved inadvertently by a young child into its
upper unlocked position is greatly reduced, that is to say the
child resistance of the cap is enhanced.
To this end, according to this invention, a safety closure cap for
fitting to an externally screw-threaded neck or side wall of a
container to close the container comprises a single integral
injection moulding of resilient thermoplastic plastics material
forming an internally screw-threaded skirt and a bowed top wall
which closes the top of the skirt and is movable with a snap action
by the application of an upward or downward force between an
upwardly bowed position and a downwardly bowed position, the top
wall having on its upper face a force-applying member enabling the
force to be applied to it and having around its periphery engaging
means which, when the cap is screwed on to a container and the top
wall is in its downwardly bowed position, engage with inward
projections on the inside of the neck or side wall of the container
and prevent unscrewing of the cap and, when the top wall is in its
upwardly bowed position, the engaging means are clear of the
projections to allow the cap to be unscrewed.
By using the top wall of the cap to form the upwardly and
downwardly movable locking part in this way, the complexity of the
operation of moving the locking part into its upper unlocked
position can be made such that it is beyond the capability of a
young child to move it either intentionally or inadvertently.
Whilst it is a simple matter to apply pressure to the top wall to
move it from its upwardly bowed position into its downwardly bowed
position, it is impossible to apply an upward force to the wall to
move it into its upwardly bowed unlocked position other than by
means of the force-applying member. The force-applying member may
be constructed in such a way as to make the application of the
necessary upward force to the top wall as difficult as may be
required.
To enable the top wall to move with a positive snap action between
its upwardly bowed position and its downwardly bowed position, the
top wall preferably incorporates two concentric annular hinges
which are formed by thin sections of the resilient plastics
material. For durability, the cap is then preferably injection
moulded out of polypropylene as it is well known that thin sections
of polypropylene can be flexed repeatedly to form hinges without
fracturing.
The top wall may comprise an annular peripheral portion which is
horizontal, this portion being connected by an outer annular hinge
to a further annular portion which extends at an upward inclination
in a radially inward direction when the top wall is upwardly bowed
and at a downward inclination in a radially inward direction when
the top wall is downwardly bowed. The further annular portion is
connected by the second annular hinge to a centre portion which
closes the space within the second annular hinge and the
force-applying member is then connected to the centre portion.
To ensure that the force-applying member cannot easily be gripped
by a young child, even by the child's teeth if the child pushes the
cap into its mouth, the force-applying member preferably comprises
an outwardly projecting flange which is connected by an upright web
to the centre portion of the top wall. The length of the web and
the shape of the flange are such that when the top wall is in its
downwardly bowed position, part of the periphery of the flange is
closely adjacent the annular peripheral portion of the top wall and
a remaining part of the periphery of the flange is in contact with
the annular peripheral portion. The web is preferably resilient and
flexible and then, in order to apply an upward force to the top
wall to move it from its downwardly bowed position to its upwardly
bowed position, downward pressure may be applied to a part of the
flange diametrically opposite the part which is in contact with the
annular peripheral portion of the top wall and this causes the
flange to tilt so that the remaining part moves out of contact with
the annular peripheral portion of the top wall. A finger can then
be inserted under the remaining part of the flange to lift the top
wall into its upwardly bowed position.
The invention also consists, according to another of its aspects,
in the combination of a closure cap in accordance with the
invention with a container having an externally screw-threaded neck
or side wall on to which the cap is screwed. The neck or side wall
of the container has on its inside inward projections with which
the engaging means of the cap engage when the top wall is in its
downwardly bowed position.
The engaging means preferably comprises a series of
circumferentially spaced lugs which move downwards and radially
outwards as the top wall is moved from its upwardly bowed to its
downwardly bowed position. The inward projections on the neck or
side wall of the container are preferably in the form of ratchet
teeth with sloping upper edges. This combination of lugs and
ratchet teeth enables the cap to be screwed on to the container
while the top is in its downwardly bowed position without damaging
the closure cap.
An example of a closure cap, and of the closure cap in combination
with a container, in accordance with the invention, are illustrated
in the accompanying drawings, in which:
FIG. 1 is a diametric section through the closure cap and through
the neck of a container on to which the closure cap is screwed
showing the top wall of the closure cap in an upwardly bowed
position;
FIG. 2 is a view similar to FIG. 1, but showing the top wall of the
closure cap in a downwardly bowed position;
FIG. 3 is a plan view of the closure cap; and,
FIGS. 4 and 5 are somewhat diagrammatic diametric sections showing
the closure cap in the course of movement of its top wall from its
downwardly bowed position to its upwardly bowed position.
As shown in FIGS. 1 and 2, a container in the form of a bottle 1
which is blow-moulded out of plastics material has a neck 2 with an
external screw thread 3. Moulded inside the open end of the neck 2
are inward projections in the form of ratchet teeth 4. There are
three of these ratchet teeth equally angularly spaced around the
inside of the neck and each of the teeth has a steep flank 5 which
extends substantially radially of the neck 2, a gently sloping
flank 6 and also a sloping upper edge 7.
The neck 2 is closed by a cap 8, which is formed as a single
integral injection moulding of polypropylene and this cap comprises
a skirt 9 and a top wall 10. The skirt 9 has an internal screw
thread 11, by which it is screwed on to the neck 2, and external
axially extending ridges 12 to enable it to be gripped
manually.
The top wall 10 comprises a horizontal annular peripheral portion
13, an intermediate annular portion 14 and a centre portion 15. The
intermediate annular portion 14 is connected to the outer annular
portion 13 by an outer annular hinge 16 and the centre portion is
connected to the intermediate annular portion 14 by an inner
annular hinge 17.
A flange 18 overlies the top wall 10 and is connected to the centre
portion 15 by a diametrically extending upright web 19. The flange
18 has a part 20 in the form of a projecting tab which is in
contact with the outer annular portion 13 when the top wall is in
its downwardly bowed position as shown in FIG. 2 and a further part
21 of the flange has its periphery closely adjacent the outer
annular portion 13 so that there is only a very small gap between
the periphery and the outer annular hinge 16.
Three lugs 22 project downwards from the underside of the
intermediate annular portion 14 and these are equally angularly
spaced around the portion 14 in the same way as the ratchet teeth 5
are spaced around the inside of the neck 2. An integrally moulded
sealing ring 23 projects downwards from the underside of the outer
annular portion 13 and the lugs 22 are so located that when the cap
8 is screwed on to the neck 2 sufficiently tightly for the sealing
ring 23 to be pressed firmly against the end of the neck 2, each
lug 22 lies in a plane just in front, in a clockwise direction as
seen from above, of the steep flank 5 of one of the ratchet teeth
4.
In use, the cap 8 is screwed on to the neck 2 with the top wall 10
in its upwardly bowed position as shown in FIG. 1 of the drawings.
With the top wall 10 in this position, the lugs 22 are clear of the
ratchet teeth 4 so that the cap can be screwed on without being
impeded in any way. When the sealing ring 23 is pressed tightly
enough against the end surface of the neck 2 to seal the bottle 1,
the flange 18 is pressed downwards so that the hinges 16 and 17 are
flexed and the top wall 10 is snapped into its downwardly bowed
position as shown in FIG. 2 of the drawings. This causes the
intermediate annular portion 14 to move from the upwardly and
radially inwardly inclined position shown in FIG. 1 to the
downwardly and radially inwardly inclined position shown in FIG. 2
and causes the lugs 22 to move downwards and radially outwards so
that one of the lugs 22 lies directly in front of the steep flank 5
of each of the ratchet teeth 4.
If any attempt is made to unscrew the cap 8 from the bottom 1 while
the top wall 10 is in its downwardly bowed position, the three lugs
22 come into contact with the flanks 5 of the teeth 4 after the cap
has been unscrewed through only a very small angle and this
prevents any further unscrewing of the cap and thus prevents the
cap from being removed.
In order to unscrew the cap 8 fully from the neck 2, it is
necessary first to move the top wall 10 into its upwardly bowed
position as shown in FIG. 1 of the drawings to move the lugs 22
clear of the ratchet teeth 4. To do this, an upward force must be
applied to the flange 18. Owing to the small gap between the part
21 of the flange 18 and the outer annular hinge 16, it is
impossible for a child to insert its fingers or even its teeth if
the cap is pushed into its mouth under the flange 18 to apply an
upward force. What is necessary is to apply pressure to a part of
the flange 18 diametrically opposite the part 20 and this bends the
web 19, which is resilient and flexible and so tilts the flange 18
and raises the part 20 clear of the outer annular portion 13 (FIG.
4). It is then possible to push a finger under the part 20 of the
flange 18 as shown in FIG. 5 of the drawings and upward pressure of
the finger on the part 20 of the flange causes the top wall 10 to
distort into the shape shown in FIG. 5. The finger can then be
moved around the underside of the edge of the flange 18 and so snap
the left-hand side of the top wall 10 upwards so that the top wall
assumes its upwardly bowed position as shown in FIG. 1. The cap 8
can then be unscrewed in the normal manner.
The procedure just described with reference to FIGS. 4 and 5 of the
drawings is however beyond the capability of a young child either
intentionally or inadvertently and in consequence the cap is highly
resistant to opening by such a young child.
The cap does, however, have the further advantage over some other
forms of child-resistant closure caps that the top wall 14 may be
kept in its upwardly bowed position when the cap is used on a
bottle in a home with no young children and then the cap may be
screwed on to and unscrewed from the bottle in the normal manner
without the nuisance of an adult having to go through the procedure
which makes the cap child-resistant.
Owing to the formation of the inward projections in the neck 2 as
ratchet teeth 5 each with an upwardly sloping edge 7, no damage is
caused to the cap if this is inadvertently screwed on to the bottle
with its top wall 14 in its downwardly bowed position and in
consequence with the lugs 22 in their downwardly and radially
outwardly moved positions. If this is done, the lugs 22 will come
into contact with the ratchet teeth 4 as the cap 8 is screwed on
and the first contact of the lugs 22 will be with the sloping edges
7 of the flanks 6.
The upward force applied to the lugs 22 by the upwardly sloping
edges 7 of the ratchet teeth will either deflect the lugs upwards
to some extent so that they ride over the teeth 4 as screwing up of
the cap proceeds, or alternatively the upward force on the lugs
will snap the top wall 10 into its upwardly bowed position. Upward
deflection of the lugs 22 is permitted by the flexibility and
resilience of the intermediate annular portion 14 of the top wall
on which the lugs are carried.
* * * * *